Is finding the right one a Science or just pure Trial and Error?
Well the answer is both, however Science plays the most important role
I have people coming to me regularly with issues associated with their saddles, perineal numbness, saddle sores, chafing, causing major PAIN and DISCOMFORT and literally ruining their enjoyment of the sport.
If you want to find the best saddle for you.... Here are the steps
1) Have the distance between your ischial tuberosities (sit bones) measured
Any good fitter or bike shop should have a measuring device. This will give you a good range indication of how wide your saddle should be to ensure proper sit bone support. Saddles usually come in 3 common width sizes 130mm, 143mm, 155mm or there abouts
Most commonly men are in the 130-143mm size, but not always
Women have a different hip structure and generally have wider sit bone distances 143-155mm,
Riding a saddle that is too wide for you can artificially spread your pelvis and cause you to ride with your knees splayed outward, resulting in poor knee tracking and potential knee injury
Riding a saddle that is too narrow can result in improper support of the pelvis causing slight collapse of the hips contributing to inward knee movement, affecting knee tracking and causing chafing of the inner thighs etc
2) Determine the right saddle profile for you
Look at the saddle from the back, you will notice that although several saddles may be the same width they all have a different profile ie one might be very flat across the back like a fizik Antares, or more rounded across the back like the fizik Arione. If you are a large person you may need the support of the wider profile and vice versa for the smaller rider.
Do I go with a saddle that has a cutout to relieve pressure on the nether regions?
This is a personal choice and if it feels more comfortable to you go for it, be aware though that cutouts can relieve pressure in one area and cause it in another.
Next time you watch the Pros in the tour, check their saddles out, You won't see a lot of cut out saddles and these guys ride 30 - 40,000 km's a year
3) Determine the type of riding style you have
If you sit very upright on the saddle you are better with a slightly wider saddle, If you ride very aggresively then a saddle on the slightly narrower end of the range might be better
If you move around a lot on the saddle pick one that is flatter from front to back like a fizik Arione. If you have a tendency to stay in one place on the saddle all the time pick a saddle with more of an up sweep to the back of it to use as a back stop. The fizik Alliante or Specialized Romin are good examples
If you move around a lot and choose a saddle with an up swept back, you could over extend your legs at the bottom of the pedal stroke if you move back on the saddle when you climb, causing tenderness behind the knees at the hamstrings insertion points
Contrary to what you might think, the longer distances you ride and the more you ride, the more saddle support you need. This translates to the more you ride the less the padding you should have.Nothing will make you more uncomfortable on a long ride than a thickly padded saddle
3) Posture is critical
The angle of your sacrum is paramount to finding the right saddle, Most people to avoid crotch pain end up rocking their pelvis back ( slumping in the saddle, causing rounding in the back ) to relieve pressure.
Avoid doing this. for it drastically affects your performance and comfort on the bike, you want to keep your sacrum and your spine neutral
4) Saddle Angle
Saddles are designed to be ridden flat +/- 1 degree, measured from the centre of the saddle forward when your bike is level, A common error people make is to level their saddles from front to back with a construction level. This results in a saddle that is tilted up at the front causing crotch discomfort and forcing you into the wrong posture.
5) Be patient
Most saddles need to be broken in, ride them at least 4-5 times before you decide that the saddle is not for you
6) Get a professional bike fit which includes a saddle fitting
A saddle that feels comfortable when you are riding in the wrong position isn't doing much for your performance, so make sure you have a proper bike fit done. Quite often saddles that feel uncomfortable are a function of poor bike fit more than anything else. You can save a lot of time and money by trying all the saddles at your fit where a professional can help you.
Whats my final TIP ??
When you find the right saddle buy several of them and put them away, for they are like GOLD and manufacturers have a tendency to change things over time.You do not want to go through the procedure all over again when you go to replace the one you have, only to find out that it has been discontinued.
Here's to riding in comfort